Improved self-acting draw-bridge



UNITED STATES PATENT OFFICE.

AUGUST KOCH, OF ROCKTOWN, PENNSYLVANIA.

Specification forming part of Letters Patent No. 35,765, (lated July l, 1862.

To all whom it may concern;

Beit known that I, AUGUST KOCH, of Rocktown, inthe county of Lycoming, in the State of Pennsylvania, have invented a new and Improved Self-Acting Draw-Bridge; and I do hereby declare-that the following is afull and exact description thereof, reference being had tothe accompanying drawings, and to the lettels of reference marked thereon, in which- Figure 1 is a ground View; Fig. 2, a longitudinal elevation. Fig. 3 is a front View. Fig. 4 is a sectional view of the cylinders.

A is the oor of the bridge; B, guides to channel-way; G C, bumpers; D E F, crosspieces to which the bumpers are secured; G, cog-wheel; H, tooth-rack secured to crosspieee E and tting cog-wheelG; I, the shaft; J, the fastenings for shaft l; K, the rudder secured to shaft I 5 L, the cylinder; M, a smaller cylinder fitting in cylinder L. N N are nuts, one with a right and the other a left handed screw. OO are screws with three threads,4

The operation is clear from the foregoing that the boat turning the bridge in its passage is'raised bythe screw in the cylinders, and the screw being of sufficient pitch to allow it to come back can only ud its resting-place `to the same, also the opening by a rudder, as

herein described, or anything else`substantially the same, and which will produce the intended effect.

AUGUST KOCH.

li tnesses:

W. H. H. MILLER, f H.MCC.L`URE. 

